화학공학소재연구정보센터
Separation and Purification Technology, Vol.182, 166-170, 2017
Selective temperature-swing adsorption of Pd(II) ions onto a poly(N-isopropylacrylamide-co-allyl mercaptan) gel
A new type of thermosensitive adsorbent gel, poly(N-isopropylacrylamide-co-allyl mercaptan) gel (NIPA-co-AM gel), was developed to improve metal separation. The thiol group of the gel selectively adsorbs precious metal ions, especially Pd(II) ions, in aqueous HCI solution in accordance with the hard and soft acids and bases (HSAB) theory. The gel adsorbed and desorbed Pd(II) ions with a change in temperature, that is, temperature-swing adsorption (TSA) was accomplished. The effects of temperature, gel composition, and HCI concentration, and the adsorption isotherms and kinetics for Pd(II) ion adsorption were investigated. The adsorption capacity of the gel with NIPA:AM = 950:50 mol/m(3) was 0.191 mol-Pd/kg-dry gel in 1 kmol/m(3) HCI aqueous solution at 20 degrees C. (C) 2017 Elsevier B.V. All rights reserved.